This application claims the priority of German application 197 03 768.2 filed in Germany on Feb. 1, 1997, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a sliding door device for a clean room.
The environment of a normal room contains fine dust, dirt particles, and mold. Penetration of such substances into rooms where precision parts, special foods, and/or chemicals are manufactured, or where surgery is performed, must be avoided. See U.S. Pat. No. 4,876,765 for background information. Special attention must be paid in particular to the design of the door for rooms of this kind, in other words, such doors must open in a relatively short time and then be closed in a sealing fashion, with the abrasion of mechanical parts, the guide and actuating devices of the sliding door for example, necessarily being low.
A known sliding door disclosed in German Patent Document, DE 32 00 497 A1, incorporates a running rail diagonal to a horizontal, on which rail the rollers of carriers connected with the sliding door rest. Seals are provided at an upper end area of the sliding door, said seals being operative when the door is closed. This design, however, suffers from the disadvantage that abrasion occurs between the rollers and the rails when the sliding door is opened and closed, said abraded particles entering the clean room as a result of the movement of the various guide parts, especially when the sliding door is closed. In addition, the channel-shaped guide rails that receive the rollers, because of the relatively large tolerances between the rollers and the guide rails, make it difficult to achieve a precise movement of the sliding door that reinforces the sealing effect. Finally, even when the sliding door is closed, undesired particles can pass through the lower boundary of the sliding door and the floor.
Hence a goal of the invention is to provide a sliding door device with a guide device that hermetically seals off the clean room in a closed state, and offers easy and reliable function. Assurance must also be provided, however, that the guide device and sealing arrangement operate and/or are designed to operate without abrasion.
This goal is achieved according to the invention by providing a sliding door device for a clean room, in which a sliding door is lowered into a closed position from an open position by means of a guide device that extends at an angle to a horizontal, and the clean room is protected against the penetration of harmful substances by a sealing arrangement when the door is in the closed position, wherein door guide devices with first and second guide members extending parallel to one another and to an actuating device for the sliding door, are provided, which guide members and actuating device are aligned accordingly at an angle, and wherein a sealing arrangement is provided which includes: a first sealing device provided at an upper end area of the sliding door, a second sealing device provided at a lower end area of the sliding door, and third and fourth sealing devices located on upright boundary areas of the sliding door.
Primary advantages achieved by the invention result from the fact that the guide device and the sealing arrangement ensure a good function of the sliding door device. By virtue of the special arrangement and design, the sealing arrangement protects the clean room against the penetration of substances that must be kept out when the sliding door is closed, such as dust, dirt particles, or the like. The guide members of the guide device, which are designed to be relatively free of wear, guarantee precise travel of the sliding door and a functionally correct position of the sealing arrangement, especially when the sliding door is closed. The guide device is mounted at an angle to a horizontal, so that it raises the first and second sealing devices, suspending their sealing functions when the sliding door is opened and lowers them back into the initial position when the door is closed, largely without wear.
The guide elements which resemble bushings and the sliding shafts create a design principle that exhibits good travel properties and takes up little space. Likewise, the second guide member can be connected with the sliding door in simple fashion by means of supporting devices installed in the adjusting devices. In addition, the actuating device is a screw drive composed of an actuating shaft and a movable member well-suited for the selected application.
The actuating assembly permits smooth closing and opening of the sliding door, which is important when the clean room is subject to heavy traffic.
The guide device is also suitable for a sliding door with two sliding door elements displaceable in a common plane. For this purpose, another guide device is employed whose actuating shaft is connected by a clutch with the actuating shaft of the other guide device (both guide devices can have the same design); for this purpose, the screw drives can be made with left-hand or right-hand threads.
An arrangement of the sliding shafts and actuating shafts that is compact as well as being favorable from the standpoint of the forces involved is achieved when, as viewed in cross-section, their centers lie on a common plane that runs at an angle to a structural plane. Finally, the sliding shafts are located at equal distances from the actuating shaft.